Electric current regulators



June 9, 1 959 L. A. INGHAM ETAL 2,890,427

' ELECTRIC CURRENT REGULATORS Filed Feb. 25; 1954 2 Sheets-Sheet 1 utl ovk 6H3 June 9, 1959 |NGHAM ETAL 2,890,427

ELECTRIC CURRENT REGULATORS Filed Feb. 25, 1954 2 Sheets-Sheet 2 35 2? 32/; 3t i g; :2}

United States Patent @fiice 2,890,427 Firtented June 9, 1959 ELECTRIC CURRENT REGULATORS Lawrence A. Ingham and John C. Davidson, Lanigan, Saskatchewan, Canada Application February 25, 1954, Serial No. 412,556

1 Claim. (Cl. 336----40) The invention relates to electric current regulators and particularly to what might be called a booster for alternating or direct current are welders and the principal object of the invention is to provide easy are starting and proper penetration at the beginning of a weld when the electrode and the metal to be welded are both cold, such resulting in easy operation and a superior quality of weld.

A further object is to provide a device for controlling current which can be used as an arc booster and built into an arc welder as standard equipment or used as an attachment to any welder.

A more detailed object is to provide a device embodying a coil connected into an electric circuit, a core associated with and under the influence of the energized coil, a spring pressed pivoted lever having its upper end connected to the core to suspend the same, adjustable means for limiting the movement of the lever and controlling the down movement of the core and valve controlled means associated with the lower end of the lever to time its movement.

A more detailed object is to provide the upper end of the lever with spaced stops operating between adjustable set screws carried by a suitably mounted, adjustable sleeve and to supply an oil tank containing a submerged cylinder with a contained spring pressed piston engaged by a finger secured to the lower end of the lever, the end of the tank remote from the finger being connected by a valve controlled pipe with the tankwhereby the setting of the valve controls the flow of oil from cylinder to the tank.

With the above more important objects in view the invention consists. essentially in the arrangement. and

construction of parts hereinafter described, reference" being had to the accompanying drawings, in which:

Fig. 1 is a side view of the device, the tank parts being broken away to expose construction.

Fig. 2 is a view similar to Fig. 1 with the lever in a changed position.

Fig. 3 is a vertical sectional view at 3-3 Fig. 1 and looking in the direction of the applied arrow.

Fig. 4 is a horizontal sectional view at 44 Fig. 1 and looking in the direction of the applied arrow.

Fig. 5 is a vertical sectional view at 5-5 Fig. 1 and looking in the direction of the applied arrow.

Fig. 6 is a perspective view showing the core, coil and other associated parts.

Fig. 7 is a wiring diagram showing how our attachment is used as an attachment for alternating current, transformer type, welders.

Fig. 8 is a wiring diagram showing how the device is used in a direct current welding circuit.

In the drawings like characters of reference indicate corresponding parts in the several figures.

In carrying out our invention we provide a suitable bracket 1 having end bearings 2 and 2 which rotatably receive the ends of a screw threaded, adjusting shaft 3 which is supplied at one end with a hand operated crank 4 for rotating the shaft. The bracket is fixedly mounted on a fixed support. On the shaft we mount a sleeve or elongated nut 5 which is suitably prevented from rotating with the shaft in order that in the rotation of the shaft, the sleeve will be end shifted on the shaft. The sleeve is supplied with similar end arms 6 and 7, that 6 extending downwardly and that 7 extending upwardly and the arrangement being such that adjustable set screws 8 and 9 carried by the ends of the arms are contained in a vertical plane laterally offset in regard to the bracket and as best shown in Fig. 5. The screws face in opposite directions and are supplied with lock nuts 10 for retaining them locked in any adjusted positions. Ro ration of the sleeve on the shaft is herein shown as prevented by a fixed guide rod 11 extending between the bearings 2 and 2 and passing slidably through the arm 7.

In a location underlying the bracket there is a fixed, horizontal tank 12 containing oil 13 and the tank is sup plied with a cross spindle 14 having suitable bearings provided on the tank sides. Secured to the spindle is a bent lever 16 having its upstanding upper end 16' clearing one side of the bracket 1 and supplied with upper and lower stops or lugs 17 and 18 positioned to become engaged with the set screws 8 and 9 in the pivoting of the lever. The lower end of the lever is extended beyond the spindle to provide a crank 16 as shown.

Within the lower part of the tank we locate a l1o1izontally disposed cylinder 19 having its one end suitably, fixedly secured to the end of the tank and in communl cation with a pipe 20 leading to the other end of the tank. The inner end of the cylinder is open to the tank interior and contains, slidably, a piston 21 which r' has its right hand end engaged by a finger 22 secured to the lower end of the crank 16 the arrangement being such that a clockwise rotation of the lever pushes the piston against a tension spring 23 located in the cylinder between the piston and the fixed endof the cylinder.

In the pipe 20 we introduce a valve 24 of any approved and appropriate type, to control the flow of oil from the left hand end of the cylinder back into the tank. Such valve is herein shown as a. needle valve to permit of fine adjustment. A tension spring 25 is secured to the lever and to any fixed base and which latter is shown as an arm 26 secured to the end wall of the tank, and such spring functions to pull the leverin an anti-clockwise direction.

Associated with the parts above described we have provided other parts now described in detail.

On a suitable fixed base 27 We mount a base member 28 of laminated silicon steel suitably bound together and on this is mounted a coil 29 of insulated copper wire. Associated with the coil is a laminated, silicon steel core 30 of a somewhat E-shape thereby presenting spaced legs or poles 31, 32 and 33 (see Fig. 4) which in the down movement of the core are adapted to take positions, re spectively, within and to the outer sides of the coil as will be readily understood.

Means is supplied to guide the core in its vertical movement and such is herein shown as vertically aligned fixed lugs 34 carried by the core and slidably receiving fixed guide posts 35 and 36 extending vertically upwardly from the base member 28.

The upper end of the core is provided with an eye 37 to which a line or cord 38 is attached and the line passes over a suitably mounted, overlying, guide pulley 39 and is secured to the upper end of the lever 16.

When the device is not in use, such as for welding purposes, the lever 16 is held by the spring 25 with the lower lug or stop 18 in engagement with the set screw 9 3 and at such time the piston 21 is in its forward position, pressed by the spring 23 against the finger 22 and the core is in its upper position above the coil.

When an arc is struck by a Welding tool, the coil is energized and the magnetic pull of the coil pulls the core downwardly at a speed determined by the setting of the valve 24, as the lever 16 cannot rotate in a clock wise direction faster than the oil within the cylinder can escape past the valve and back into the tank. This has the effect of gradually decreasing the welding current due to the increase of the reactance of the coil be down movement of the core is determined by the position in which the upper end of the lever is stopped by the set screw 8 and thereafter the current in the welding circuit remains constant or unchanged.

Subsequently when the are at the electrode is broken, the pull of the spring immediately returns the core to its up position, the stop 18 being then in contact with the set screw 9. The piston 21, however, under the influence of the spring 23, moves back slowly to its original position such being due to the setting of the valve. Following this if an arc is immediately again struck at the electrode of the welding tool, this occurring when the work (metal) is still hot, the core 30 can move to its lower position very quickly thus giving a very short boost of current in the welding circuit such being pos sible because the piston has not had time to return to its forward position against the finger 22.

Later, if an are be struck, say in a few seconds, and after the metal being welded has had time to cool, and a long boost of current in the welding circuit is required, this is possible for the reason that the piston has meantime returned into contact with the finger and the core is free to again move down to the position as determined by the contact of the lever with the set screw 8 and timed by the setting of the valve 24.

The welding current is adjusted by operating the hand crank 4 as required, and obviously such will shift the sleeve 5 with its end arms to any desired position where it will remain. It will be noted that the amount of free movement permitted the lever between the set screws 8 and 9 is only part of the total movement or stroke of the core, in respect to the coil and such free movement is quite sufficient for boosts and further it will be seen that the length of the boost stroke of the core decreases as current is set for lower values by increasing the angle of the lever in respect to the set screw 8. The time the boosting current lasts is controlled by the setting of the valve 24.

When used as an attachment for alternating current, transformer type welders, the current control of the '4 welder itself is set at a maximum and the booster attachment is then used both as a booster and current control mechanism. Such arrangement is shown in Fig. 7.

When used with a direct current welder, where the coil offers no resistance to the current an arrangement such as shown in Fig. 8 can be employed. The welding current is still passed to the coil 29 and the current setting is still controlled by the lever 16 which is connected by a link 40 to a rheostat 41 introduced in the field coil circuit of the direct current generator 42 and thereby controlling the current. The link arrangement is such that when the core is in its lower position the rheostat offers greatest resistance, with the result that the generator delivers a minimum current and such that when the core is in its up position the rheostat offers minimum resistance and the generator delivers maximum current.

For use as a built in feature on an alternating current welder, all that is required besides this device is a trans former to change the line voltage to proper welding voltage.

What we claim as our invention is:

In an electric welding system, means to control the movement of a magnetic core into and out of a magnetic base member supplied with an energizing coil, said means comprising, a pivoted lever connected to the core to permit the latter movements into and out of the core, a tension spring connected to the lever and operating to withdraw the core from the base member, stop means to engage the lever in the out position of the core, further stop means provided to engage the lever to limit a desired innermost position of the core within the base member, a fluid tank, a cylinder submerged in the tank and having one end open and the other end closed, a bypass pipe leading from the closed end of the cylinder and returning to the tank, an adjustable valve inserted in the by-pass pipe to control fluid flow therethrough, a piston within the cylinder and spring pressed towards the open end thereof and a member secured to the lever and entering the cylinder to engage and shift the piston upon the coil becoming energized.

References Cited in the file of this patent UNITED STATES PATENTS 684,166 Baker Oct. 8, 1901 914,892 Storer Mar. 9, 1909 1,343,201 Eschholz June 15, 1920 1,676,282 Philps July 10, 1928 1,893,771 Garman Ian. 10, 1933 2,158,916 Theodore May 16, 1939 2,419,892 Graves Apr. 29, 1947 

